count_if.cpp 1.2 KB

1234567891011121314151617181920212223242526272829303132
  1. // Copyright Louis Dionne 2013-2017
  2. // Distributed under the Boost Software License, Version 1.0.
  3. // (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
  4. #include <boost/hana/assert.hpp>
  5. #include <boost/hana/count_if.hpp>
  6. #include <boost/hana/equal.hpp>
  7. #include <boost/hana/ext/std/integral_constant.hpp>
  8. #include <boost/hana/integral_constant.hpp>
  9. #include <boost/hana/mod.hpp>
  10. #include <boost/hana/not_equal.hpp>
  11. #include <boost/hana/tuple.hpp>
  12. #include <boost/hana/type.hpp>
  13. #include <type_traits>
  14. namespace hana = boost::hana;
  15. using namespace hana::literals;
  16. auto is_odd = [](auto x) {
  17. return x % 2_c != 0_c;
  18. };
  19. int main() {
  20. constexpr auto ints = hana::tuple_c<int, 1, 2, 3>;
  21. BOOST_HANA_CONSTANT_CHECK(hana::count_if(ints, is_odd) == hana::size_c<2>);
  22. constexpr auto types = hana::tuple_t<int, char, long, short, char, double>;
  23. BOOST_HANA_CONSTANT_CHECK(hana::count_if(types, hana::trait<std::is_floating_point>) == hana::size_c<1>);
  24. BOOST_HANA_CONSTANT_CHECK(hana::count_if(types, hana::equal.to(hana::type_c<char>)) == hana::size_c<2>);
  25. BOOST_HANA_CONSTANT_CHECK(hana::count_if(types, hana::equal.to(hana::type_c<void>)) == hana::size_c<0>);
  26. }